On 17/06/25 06:10, Kugan Vivekanandarajah wrote:
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Hi,
As discusses earlier, get_original_name is used to match profile binary names to
the symbol names in the IR during auto-profile pass.

I think it could be good to add a link to the mailing list archive for this.


Hence, we want to strip the compiler added suffixes for names
that are generated after auto-profile pass.

Names we should strip:
* SRA clones (of the form foo.isra.0)
* IPA-CP clonse (in the form bar.constprop.123)
* Partial inlining clones (foo.part.0, foo.cold)
* lto_priv.0
* Nested function as foo.part.0

Others that should not be stripped:
* target_clones (foo.arch_x86_64_v2, foo.avx2)
* OpenMP related suffixes (.omp_fn.N, .omp_cpyfn.N)

Tested by running autoprofiledbootstrap and tree-prof check that
exercises auto-profile pass.

gcc/ChangeLog:

         * auto-profile.cc (isAsciiDigit): New.
         (get_original_name): Strip suffixes only for compiler generated
         names tat happens after auto-profile.

Thanks,
Kugan

diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
index e12b3048f20..c787bf2d220 100644
--- a/gcc/auto-profile.cc
+++ b/gcc/auto-profile.cc
@@ -345,16 +345,50 @@ static gcov_summary *afdo_profile_info;
/* Helper functions. */ +bool isAsciiDigit (char c)
+{
+  return c >= '0' && c <= '9';
+}

Not sure about the naming conventions, and slight nit, sorry,
but shouldn't this be snake case, like 'is_ascii_digit'? Also,
it looks like GCC has an `ISDIGIT` macro, could that be used
instead?

+
 /* Return the original name of NAME: strip the suffix that starts
-   with '.' Caller is responsible for freeing RET.  */
+   with '.' for names that are generetad after auto-profile pass.
+   This is to match profiled names with the names in the IR at this stage.
+   Caller is responsible for freeing RET.  */
static char *
 get_original_name (const char *name)
 {
   char *ret = xstrdup (name);
-  char *find = strchr (ret, '.');
-  if (find != NULL)
-    *find = 0;
+  char *last_dot = strrchr (ret, '.');
+  if (last_dot == NULL)
+    return ret;
+  bool only_digits = true;
+  char *ptr = last_dot;
+  while (*(++ptr) != 0)
+    if (!isAsciiDigit (*ptr))
+      {
+       only_digits = false;
+       break;
+      }
+  if (only_digits)
+    *last_dot = 0;
+  char *next_dot = strrchr (ret, '.');
+  /* if nested function such as foo.0, return foo.  */
+  if (next_dot == NULL)
+    return ret;
+  /* Suffixes of clones that compiler generates after auto-profile.  */
+  const char *suffixes[] = {"isra", "constprop", ".lto_priv", "part", "cold"};

".lto_priv" should just be "lto_priv" here.

+  for (unsigned i = 0; i < sizeof (suffixes); ++i)
+    {
+      if (strncmp (next_dot + 1, suffixes[i], strlen (suffixes[i])) == 0)
+       {
+         *next_dot = 0;
+         return ret;
+       }
+    }
+  /* Otherwise, it is for clones such as .omp_fn.N that was done before
+     auto-profile and should be kept as it is.  */
+  *last_dot = '.';
   return ret;
 }

It looks like this function only strips the first suffix? I don't think this
would work for functions with multiple suffixes like "bar1.constprop.0.isra.0",
where an IPA-CP clone has an SRA clone created for it. I haven't tested the
patch, but I think it would return "bar1.constprop.0" for the above function
name, whereas the current implementation returns "bar1" as expected.

--
Regards,
Dhruv

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